1. Technical Field
This disclosure relates to memory arrays and, more particularly, to column redundancy implementations.
2. Description of the Related Art
Many memory implementations use column redundancy to enable a memory array to be used even if the array has been manufactured with one or more bad bits or memory cells. Having a redundant column allows the array to be repaired. One conventional way to implement column redundancy uses a two to one multiplexer (mux). In such an implementation if a bit is bad, the mux may be used to simply shift a certain number of the bits to the next column from the bad column and to use the redundant column. However, in such conventional implementations, when a write occurs the redundant column gets written even when the redundant column isn't being used. Similarly, when the redundant column is being used to repair a bad column, the now bad/unused column may also continue to be written. This writing of data to the unused column causes toggling of the logic in the unused column, and since a column may include many bits considerable excess power may be consumed. In many applications, and particularly in mobile applications, excess power consumption may be unacceptable.